Disk tool



Jan. 5, 1937. F..o. ALBERTsoN 2,066,381

DISK Toor..

Filed Jan. 18, 1935 12 wie@ y fwwflerisazc Patented Jan. 5, 1937 PATENT osi-lcs DISK TOOL 0. Albertson, Sioux City, Iowa, assignor to Albertson & Company, Inc., Sioux City, Iowa,

Ya corporation of Iowa Application January 1s, 19,25, serial No. 2,339

3 Claims.

The present 'invention relates to abrasive disk to1s,.and is particularly concerned with devices for-enabling the users of abrasive disks or the like to fully utilize the abrasive area of the ma- 5 ;terial ofwhich the diskis made.

l The abrasive disks to which reference has been made'are used upon flexible supporting pads of the type covered by my prior Patent No. 1,882,693, October 18, 1932, Abrasive device, and it is frequently found that the outer edge of the diskis subjected to the greatest amount of use and wear. The central portion of the disk may then still be ingood condition and capable of further use.

One of the objects of the invention is the proi visionof an improved tool by means of which therused portion of the disk may be cut 01T.

Another object of the invention is the provision ofV anA improved cutting tool by means of which the used parts of anabrasive disk may be trimmed oi andthe abrasive putin proper condition for `use on a smaller supporting pad,

Another object of `the invention is the provision of`- an improved tool of the class described, which isr adapted to beused for trimming abrasive disks of various sizes to successively smaller sizes suitable for various smaller supporting pads.

Another object of the invention is the provision of an improved disk cutting tool of the class described, which is simple, sturdy, economical and peculiarly adapted to the quick and clean cutting or trimming of abrasive disks with a minimum amount of effort, in order to utilize fully all of the area of the abrasive material.

Other objects, features and advantages of the A invention will be apparent from the following description and the accompanying drawing, l in which similar characters of reference indicate similar parts throughout the several views.

Referring to the single sheet of drawings,

Fig. 1 is a top plan view of the present tool;

Fig. 2 is an elevational view in partial section taken on the plane of the line 3-3 of Fig. 1, the

cutting'board and abrasive being shown in section; Y

Fig. 3 is a sectional view, with most of theparts ofthe tool in section, taken on the plane of the line 3-f-3 of Fig. 1,looking in the direction of the arrows;

Fig. '4 is a fragmentary detail sectional view,

50,. taken on the plane of the line V44 of Fig. 3, with the 'cutter in elevation; l -Y Y `Fig. 5 is a fragmentary'detailed sectional view,

taken on 'the-'planevof the line 5 5 of Fig. 3, showing the structure of the securing means forA 5th-the cutter support.

'Ihe complete toolv equipment preferably includes a relatively hard flat cutting board such as a piece of oak or other suitable material, against which the abrasive sheet may be placed for the cutting operation. 1 5

The board I 0 is preferably provided with a centrally located aperture II, which is of materially larger size than therdownwardly projecting trunnion I2 which passes through the aperture in the disk I3. The aperture II is larger 10 than the trunnion I2 so that the grooving which results from a cutting operationV comprising a circle on the board will not always strike the same part of the board. However, the trunnion I2 and aperture II serve to substantially center 15 the cutting tool with respect to the board I0.

The abrasive disks I 3 are usually made of relatively stiif material covered with abrasive such as emery Vor carborundum upon the one side, and they are formed with a centrally located aperture I4 for passing a drive shaft or'securing screw bolt and a preformed depression I5 in the face of the disk for receiving the athead of the securing member which passes through the aperture I4. The abrasive should be placed face downward upon the board I0, and the trunnion I2 of the tool should be inserted in the aperture I4 for the cutting operation.

The cutting tool preferably comprises a substantially cylindrical stud I6 provided with a reduced cylindrical portion comprising trunnion I2, and with the intermediate annular shoulder II. The cylindrical stud I6 is provided with an axially threaded bore I8 for receiving the threaded end of the screw bolt I9, the head 20 of which retains the knob 2I which is rotatably supported on the screw bolt I9.

The stud I6 is also provided with a transverse cylindrical bore 22, within which is xed the cylindrical end 23 of a radial arm 24 by means of- 40 a transverse pin 25. The arm 24 is preferably rectangular in cross section except for the cylindrical end 23, and is preferably provided with a plurality of stop members 25, 26, 21. These stop members may comprise screw bolts which are 45 threaded home in the complementary threaded bores provided in the radial arm 24 and located at suitable Vradii from lthe center of theV stud I6.

The standard size of abrasive disk is always one eighth of an inch over size so as to over` 50 lap'the holder, and on some jobs even greater overlaps are desired so that for such purposes the holder may have its cutter set at any desired radius. However, the usual sizes of abrasive disks are nineinches, seven inches, ve inches, g

' with its axis in alignment Vwith the axis of av and three inches, andthestops-25, 26, 21 are so located that when the side of the holder 28 engages the head of any stop or bolt 25-21, the cutter 29 is located at a suitableradius to cut the standard size of disk. The largest size of disk may be cut by placing the holder `28 outside of the stop 25 on the arm 24.

The holder 28 comprises a block of steel, all of stud I6, which is the center of rotation.

The holder 2s is also provided with a threaded' bore for receiving a clamping screw by means of which it may be secured at any desiredv position on the arm 24.

Upon its upper end the holder 28 is provided with a threaded bore 3| threaded end of the screw bolt 34 which rotatably Y supports the knob 35. In its lower end the hold- Vforming a cutting edge at the periphery of the Atrunnion I2 so as to retain the member 44 on 'A 45, the disk being clamped between the flange` er is provided with a longitudinally extending slot 36 of suicient width to rotatably receive the circular cutter 29. The block 28 is also provided with the bore 31 communicating with counterbore 38 for receiving the cylindrical head 39 and the cylindrical body 40 of a screw bolt which serves as a journal for the cutter 29. The screw bolt 39, 49 may also be provided with an annular shoulder 4| so that the bolt may be secured tightly in'place by a nut 42, the cutter 29 being mounted for rotation on the cylindrical portion 39.

Cutter 29 comprises a circular disk of best hardened tool steel provided with a bevel 43 disk. The cutter is preferably arranged with its bevel outward with respect to the center of the tool.

In order tol hold the abrasive disk in place the trunnion` I2 also rotatably supports or is rotatably supported upon a cup-shaped member 44 which may be formed of a sheet metal stamping having a circular body and a downwardly extending cylindrical ilange 45. An upwardly ex- 'tending cylindrical flange 46 forlns a bearing for the trunnion I2 by engaging the annular shoul-A der I1.

The member 44 is preferably provided with a vwasherplate 41 which may be spot welded to the body of the member 44 at a plurality of points,

and which provides the body withY a relatively sharp retainingshoulder at the point 48 for engaging the split wire ring 49. is sprung into a groove; 50 suitably located in the the trunnion I2. Member. is, therefore, adapted to rotate with respect to trunnion I2. andmay be utilized by means of the knob 2| forpressing down on the disk I3 at the end 5I of theflange 45 and the board I0. M y The method of use of the tool is as follows: The abrasive is placed face down on the board I0 and thecutter 29 located atY the proper radius; so as to trim off 'the usedportion of the disk..

The knob 2I may be. pressed down to hold the disk I3 in fixedposition on the board and the cutter may be Worked back and forth by pressing down.v on theknob 35...-and movingit back and for receiving the.

'Ihe split wire ringy forth in a circle determined by the arm 24. As the cutter 29 cuts through the abrasive disk, the operator may relieve the pressure on the knob 2| and taking hold of the edge of the disk rotate the disk around to such a point that itis again s in convenient position` to cut a short arc of a disk by means of the cutter 29, and thus by successivecuts the used part of .the disk is cut from the. periphery of -the diskjand theydlslj is reduced in size tothe next standard abrasive disk 10 fora smaller supporting pad. When the edge of the disk has again been used, assuming that the .center portion is still in good condition, a further cut may be made oif the edge of the disk, and thus the disk may be used a plurality of times 15 until its use on the smallest type of supporting disk for-use. f

It will thus be observed that I have invented an improved tool by means of which abrasive 20 disks of the type described-.may be trimmed! down and the abrasive areaV thereof .f1ll1y.utilized, ale though the greatest :amolmtof we'aror,use emraes.` at the edge of` the abrasive disk.

The present tool is simple, sturdy, ycompact-25 and will save its cost ina very short timein the saving reflected .by more economical use .of ab rasive disks. The purchaser or user may then buy the larger sizes of disks and use the central` portions` of the larger. disks forsmaller abrasive.. 30 disks by trimming off the consumed orused por.- tion of the abrasive. disk. f

While I have illustratedv a preferred ,embodiment of my invention, many modifications maybe made without departing from the spirit ofthe,35 invention, and I do not wish to be` limited tothe precise details of construction setforth, but ldesire to avail myself of all changes within the; scope of the appended claims.

Having thus describedmy invention, whatwl; 40e

claim as new and desire to secure byLetters Pata. ent of the United States, is:. ,Y yg.

1. In a disk cutting tool, the combination of a supporting shaft with a radially extending arm,.a. holder adjustably mounted on said arm, Aa disk 45 cutter carried by said holder, a clamping member carried by said shaftcomprising a cup shaped member having a. depending ange for engaging and holding a sheet, said shaft projectinguinto said cup to engage in an aperture in the sheet 5m to hold said .sheet lin predetermined position :said i shaft having a groove located therein, and aresilient metal member engageable in said groove and projecting therefrom sufficiently to; engage and retain said cup 1shaped member on said shaft. n

. 2. In an; abrasive disk tool, thecombination jof a suitable support with a tool having `a. vertically extending trunnion, a member havinga depend.- ing flangek carried by said trunnion for enwing andsecuringan abrasive sheet jwhen pressure .is om f applied to said handle, a radially extendingl arm Vmounted on said arm, and a handle rotatably,

mounted on said` member-for ,f the applicatienj` .of

pressure to, said ...cutters l Y .Y f l; ds. In an abrasive disk tool, tneoomloioation or! a suitable. support with a tool hevige Yertiallyf extending trunnionga relatively hard flat cutting board having a centrally located aperture of terially larger size than the ahandle'u I,

on said arm,- a'nd means fo' secu'riig slid cutter in any of a plurality of predetermined positions, said cutter being carried by a metal member slidably mounted on said arm, and a handle rotatably mounted on said member flor the application of pressure to said cutter. l

FRANS 0. ALBERTSON. 

